Aimi, sweating profusely, intertwines with her ex-boyfriend Okuda. She reveals to her ex that she plans to restart her relationship with her husband during their summer vacation and informs him of their trip to a ryokan in Kusatsu. One day, she meets her husband's brother, Tsuyoshi, who expresses his desire to join them, causing her confusion. At the ryokan, Tsuyoshi's forceful advances begin to unfold...
